Given that OAM is a modulation technique, which is a physical-layer tech, nothing above firmware will even know about it. At most software will be able to read/set a flag enabling use, similar to FX/DX on Ethernet.

I think its more than that. When you exceed by an order of magnitude the bitrate, different APIs will be needed to take advantage. Sure you can just send on a socket, but it will max out at the rate you can call that API (including kernel switch, copying data, waiting for a completion interrupt etc).

Some kind of virtual hardware or mapped memory will be desirable to achieve great leaps in bandwidth usage.